Problem: Expand.
Explanation: $\begin{aligned} &\phantom{=}(2a^2 + 7a - 10)({a-5}) \\\\ &=(2a^2 + 7a - 10)({a})+(2a^2 + 7a - 10)({-5}) \end{aligned}$ $\begin{aligned} &=2a^3+7a^2-10a-10a^2-35a+50 \\\\ &=2a^3-3a^2-45a+50 \end{aligned}$